TingTongPJ

iTrader: (24)

can any one help please have fitted a amp to my car and now i get a engine/transmission whine through the speakers. sure i have to fit something to get rid of it but can't remember what and where in the wiring. been a long time since i fitted anything like it. any help appriciated.

sti-chris

you need to fit a supressor,
any decent car audio store , or halfords do these.

BigRed

A very common problem this one and takes some getting rid of.

There are many causes for this, and normally fitting a suppressor don't cure it.

How good is your earth connection for the amp, did you connect it to BARE metal with no paint on the surface?? If not then scrape away any remaining paint, refit the earth cable using a bolt and not a self tapping screw and then you can repaint the area, don't use seat mounting bolts for earthing your amp. Also the quality of you RCA leads and where you have run them in the car make a difference, poor quality RCA leads don't tend to have the shielding needed for an in car environment which is inherently noisy. If you have run these leads next to power cables or the cars OEM wiring harness then relocate them away from these, also running RCA leads next to speaker cables can, but not likely, be a problem.

Make sure the earth on you head unit is good also, you can always re-earth the head unit.

You could try one of these http://www.m-99.co.uk/Car_Audio/Nois...uppressor.html this fits in line with your RCA leads, as close to you amp as possible, they do work OK in my experience, but cut off low frequencies below 40hz, so no good if you want to run a sub.

TingTongPJ

iTrader: (24)

thanks first i'll try moving the earth its connected to the metal plate by the gearbox so reading above maybe thats the problem.

Dease

iTrader: (3)

Have you run the speaker wires/RCA's next to the power and amp switch wires?

Run them on seperate sides of the car if you have

BlueBugEye

iTrader: (12)

Sounds like a ground loop to me. Caused by a difference in resistance between the two earth points, try running your H/U earth to the same point as the amp earth. You can do this as a temporary measure to test the theory - just make sure the earth wire is a heavy enough gauge.